The MOLECULAR VIROLOGY CORE in this CFAR proposal will provide equipment, materials, and expertise for supporting research projects that require molecular cloning, radioactive and non- radioactive probes, synthetic oligonucleotides, expression vector systems, DNA sequencing, and analysis of viral and cellular macromolecules (polypeptides, RNA, and DNA). These projects involve several retroviruses including human immunodeficiency viruses types 1 and 2 (HIV-1 and HIV-2), simian immunodeficiency viruses (SIV) from rhesus macaque and sooty mangabey monkeys, feline T-lymphotropic virus (FTLV), simian AIDS-associated retrovirus (SRV, a type D retrovirus), bovine immunodeficiency-like virus (BIV), visna virus, and caprine-arthritis-encephalitis virus (CAEV) as well as several DNA viruses (e.g., rhesus and human cytomegaloviruses, rhesus Epstein-Barr virus, rhesus denovirus, vaccina virus). These activities in the MOLECULAR VIROLOGY CORE involve many direct interactions with investigators in both the PRIMATE CENTER and the CLINICAL VIROLOGY CORES.